Two-stroke-cycle valveless internal-combustion engine



Dec. 9, 1924. 1,518,983

J. HYVERNAUD TWO-STROKE CYCLE VALVELESS INTERNAL COMBUSTION ENGINE Filed July 3.5, 1922 2 Sheets-Sheet 1 @ea. 1924 L51 J. HYVERNAUD TWO-STROKE CYCLE VALVELESS INTERNAL COMBUSTION ENGINE Filed July 15, 1922 2 Sheets-Sheet 2 Patented. Dec. 9, 1924-.

UN T STATES. OFFICE. Y H was mrvmn a 015095315,

Application flied July 18, 1821i. Sci-12.1110. 574,745.

To all whom it may concern.

Be it known that I, JACQUES Hrvnnnapn, a citizen of the French Republic, resid ng at Paris, in the Department of the Seine, France, have invented certain new and useful Improvements in Two-Stroke-Cycle Valveless Internal-Combustion Engmes, of which the following is a specification.

This invention relates to a two-stroke cycle valveless internal combustion engine which is characterized by the simplicityof' its working due to .itsconstructmn which also allows of rapid assemblage and disassemblage of the engine.

This engine formin the sub ect matter of the invention is herelnafter described and illustrated in the drawings attached to the present specification in which:

Figure 1 is a diametral-sectio showing the parts in the positions they ocdhpy when the piston is on the upper dead centre.

Figure 2 is a similar view when the plston is on the lower dead centre.

Figure 3 is a vertical sectional new of a portion of the inside face of the cylinder showing the section of the exhaust or fice .As shown, in the drawings the engine consists of a c' linder 1 comprising as usual the apertures or the sparking plugs and the pressure-relieving devices, the water circulation passages etc.

In this cylinder 1 there are formed one, two or more exhaust parts or orifices 2 so arranged as to be completely uncovered at the moment when the piston reaches the lower dead centre.

These orifices 2 which open into the exhaust collectors 3 have the characteristic feature that the upper part 4 of their wall has the form. of an inverted V as shown in Figure 3. This peculiar section 4 having the form of an inverted V which is given to the exhaust orifices 2 is designed to diminish the noise made by the burnt gases in exhausting suddenly from the cylinders in the sense that the exhaust takes place gradually by reason of the fact that as the piston uncovers the orifice 2 the gases escape first in the form of a jet at the apex of the inverted V, then in the form of a triangular 'et of increasing section until its section coincides with the complete section of the orifices 2.

Below the exhaust orifices 2 as well as below the sleeve piston when it is on its upper dead centre there are arranged one, two or more admission parts or orifices 5 o ning into the interior of the cylinder 1. inally the lower portion of the wall 1 ofthe cylinder whose base 6 is fixed to the upper part of the support or casing 7 comprises in its thickness an annular chamber 8 of suitable capacity the use of which is hereinafter set forth. j

The cylinder 1 constructed and characterized as above stated is mounted upon the casing7 after the previous insertion inside those two constituent parts of the'engine of a cylindrical sleeve 9 which is kept centred and in its correct position by means of a circular flange 10 clamped between the flange 6 of the cylinder 1 and the flange of the casing 7.

This sleeve which opens at its lower end into the casing and is c osed at its upper end 11 projecting into the cylinder 1 has a chamber or chambers such as to enable said sleeve to constitute a kind of internal 'ack st for the casing 7 leaving an annular c amber 12 between it and the inner inside wall of the cylinder 1. This annular chamber communicates with the chamber 8 of the cylinder 1 at the base of the latter as shown at 13 either by reducing the height of the said wall or by formin wide apertures or notches therein. Thls sleeve 9 thus separates the casing 7 from the cylinder 1 in a gas-tight manner. It serves at the same time as a slide-way for a slide block 14 connecting the driving piston rod 15 to the rod 16 of the piston 17, this rod working through the end 11 in a stufiing-box 18 of any suitable design. This rod 16 is hollow throughout the greater portionof its length and it terminates at the top or .inner surface of the iston 17 at the centre thereof; it comprises 1n its portion situated below and between the iston 17 when the latter is at the lower dea centre, and the end 11 of the sleeve 9, apertures 19 which establish communication between its hollow chamber 20 'and the free space 21 situated below the pis-- communication with the chamber 25 of the of the engine, the total spaces 20 and 24 ofthe rod 16 and of the tube 23 constitute a chamber whose volume will vary according to the position of the piston 17. This being the general arrangement the two-stroke cycle engine characterized by its cylinder, its inner jacket and the central arrangement of the piston rod and hollow tube for guiding the piston and its chamber of varying volume operates as follows:

In the position shown in Figure 1, the piston being on its upper dead centre the explosive mixture is compressed to its maximum degree between the engine head and the piston 17 in the chamber 25. At the same time the admission orifices 5 being uncovered by the sleeve 22 of the piston 17 the fresh gases will enter the space 21 below the piston, passing through the annular chamber 12 between the sleeve 9 and the base of the cylinder, and through the annular passage 13 into the chamber 8 formed in the thickness of the wall of the cylinder 1.

The totality of these spaces at chambers 21, 12 and 8 will be filled the more rapidly as during the upward movement of the piston and so long as the admission orifices 5 are not uncovered there is produced a certain degree of rare-faction which enables the engine to run at high speeds.

After having passed the upper dead centre and explosion havin taken place the piston 17 in moving down 1n order to make its power stroke, gradually reduces the space 21 with the result that nearly the whole of the fresh gases are enclosed in the spaces 12 and 8 whose whole capacity has been designed for this purpose.

Shortly before the piston reaches the lower dead centre the exhaust orifices 2 for the burnt gases become uncovered while the admission orifices 5 have been closed at the very beginning of the down stroke of the piston as is ordinarily the case.

In the position shown in Figure 2 the piston being on its lower dead centre the fresh gases enclosed in the chambers 8 and 12 as well as in the space 21 which is reduced to its minimum below the piston, will enter the chamber of varying capacity constituted by the chambers 20 and 24 of the piston rod 16 and the fixed tube 23 because at that moment the apertures 19 of the piston rod 16 are no longer closed by the tube 23, so that the fresh gases can pass into the chamber 25 of the cylinder 1 through the aperture 26 of the tube 23; this admission is accelerated thereby and it helps at the same time the expulsion of the burnt gases by the return of the piston 17 which causes a diminution of the varying-volumechamber 2024; the orifice 26 being closed at the .lnoment mounted in the holes in t e cylinder head shown in the drawings.

In addition to the advantages due to the simple working of this engine thus constituted, it is to be noted that the com bination of the cylinder mounted upon the casing with the inte osition of the flange 10 of the sleeve 9 al ows of rapid assem' bling and disassembling because the centering of these parts is effected mutually and automatically.

It is to be understood that modifications, alterations and improvements may be made in the arrangement, form and dimensions of the characteristic elements constituting the engine as well as in their combination and in the means for carrying into practice without departing from the essential nature of the said invention. For example, as regards the chamber 8 there may be only one such chamber, or in its stead there may be a plurality of chambers or compartments interconnnunicating or not intercommunieating, their total capacity being equal to that of a single chamber whose volume is adapted according to requirements; this single chamber 8 or chambers or compartments provided in its stead being as already stated formed in the thickness of the wall of the cylinder or they may be attached to the cylinder.

In some cases the said chamber 8 or the chambers may instead of being formed in the wall of the cylinder be formed in the wall of the upper part of the casing 7 or be attached to the latter, communication with the annular space 12 being assured by orifices opening thereinto which are formed in the thickness of the flange 10 of the sleeve 9 in any suitable manner capable of producing the same result as does the constructional form which has been illustrated by way of example in the accompanying drawings.

What I claim is:

1. In a two-cycle valveless internal combustion engine, the combination with a support, of a cylinder having inlet and outlet ports, a suitably mounted, stationary sleeve extending into the chamber of said cylinder but being of a lesser diameter than said chamber, thus leaving an annular chamber between said sleeve and the inner wall of Said cylinder, said annular chamber communicating with said inlet ports, said cylinder beingprovided with an annular chamber outside of and communicating with said first-named annular chamber, a piston working in said cylinder past said ports and of suitable extent to uncover the inlet ports at the end of each compression stroke, and to uncover the outlet ports at the end of each power stroke, a tube carried by said piston and having ports communicating with said first-named annular chamber, a stationary tube telescoping into said first-named tube and having ports opening into the chamber of said cylinder, said ports in said stationary tube being so arranged as to be closed at the end of each compression stroke of said piston, so that explosions will occur in the chamber of said cylinder.

2. In a two-cycle valveless internal combustion engine, the combination with a support or cas1ng,of a cylinder having inlet and outlet ports, a sultably mounted, stationary 1 ing an annular chamber between said sleeve sleeve extending into the chamber of said cylinder but being of a lesser diameter than said chamber, thus leaving an annular chamber between said sleeve and the inner wall of said cylinder, said annular chamber communicating with said inlet ports, said cylinder being provided with an annular chamber outside of and communicating with said first-named annular chamber, a piston working in said cylinder past said ports and of suitable extent to uncover the inlet ports at the end of each compression stroke, and to uncover the outlet ports at the end of each power stroke, a tube carried by said piston and having ports communicating with said first-named annular chamber, and a stationary tube telescoping into said first-named tube and having ports opening into the chamber of said cylinder, said ports in said stationary tube being so arranged as to be closed at the end of each compression stroke of said piston.

3. In a two-cycle'valveless internal combustion engine, the combination with a support or casing, of a cylinder having inlet and outlet ports, a sleeve having a flange interposed between said support or casing and said cylinder, said sleeve extending into the chamber of said cylinder but being of a lesser diameter than said chamber, thus leavand the inner wall of said cylinder, said annular chamber communicating with said inlet ports, said cylinder being provided with an annular chamber outside of and communicating with said first-named annular chamber, a piston working in said cylinder past said ports and of. suitable extent to uncover the inlet ports at the end of each compression stroke, and to uncover the outlet ports at the end of each power stroke, a tube carried by said piston and havin ports communicating with said firstname annular chamber, and a stationary tube telescoping into said first-named tube and having ports opening into the chamber of said cylinder, said ports in said stationary tube being so arranged as to be closed at the end of each compression stroke of said piston.

4. In a two-cycle valveless internal combustion engine, the combination with a support or casing, of a cylinder having inlet and outlet ports, a suitably mounted, stationary sleeve extending into the chamber of said cylinder but being of lesser diameter than said chamber, thus leaving an annular chamber between said sleeve and the inner wall of said cylinder, said annular chamber communicating with said inlet ports, said cylinder being provided with an annular chamber outside of and communicating with said first-named annular chamber, a. piston working in said cylinder past said ports and of suitable extent to uncover the inlet ports at the end of each power stroke, a tube carried by said pistonand having ports communicating with said first-named annular chamber, a stationary tube telescoping into the said first-named tubefand having ports opening into the chamber of said cylinder, saidports in said stationary tube being so arranged asito be "closed at the end of each compression strokeof said piston, and a pistonrod sli -block fitting in said sleeve below said pi ton. A

In testimony whereof I afiix my signature, in presence of two witnesses.

JACQUES HYVERNAUD.

Witnesses LUGIEN CRnsrIN, CHARLES Damn. 

